1. Field of the Invention
The present invention relates generally to impedance matching in the construction of high frequency circuits, and more particularly relates to connection schemes for reducing impedance mismatches between conductive traces and components coupled thereto.
2. Background Information
With advances in integrated circuit, microprocessor, networking and communication technologies, an increasing number of devices, in particular, digital computing devices, are being networked together. Such devices are often first coupled to a local area network, such as an Ethernet-based office/home network. In turn, the local area networks are interconnected together through wide area networks, such as Synchronous Optical Networks (SONET), Asynchronous Transfer Mode (ATM) networks, Frame Relays, and the like. Of particular importance is the TCP/IP based global inter-network, the Internet. The rapid growth of the Internet has fueled a convergence of data communication (datacom) and telecommunication (telecom) protocols and requirements. It is increasingly important that data traffic be carried efficiently across local, regional and wide area networks.
As a result of this trend of increased connectivity, an increasing number of applications that are network dependent are being deployed. Examples of these network dependent applications include, but are not limited to, the World Wide Web; email, Internet-based telephony, and various types of e-commerce and enterprise applications. The success of many content/service providers as well as commerce sites depends on high-speed delivery of a large volume of data across wide areas. In turn, this trend leads to an increased demand for high-speed data trafficking equipment, such as high-speed optical-electrical routers or switches and the like. In other words, as a widening variety of new and traditional services converge across shared inter-networking transport structures, there is a critical need for the Internet to simultaneously deliver higher bandwidths, more reliable service, and greater deployment flexibility.
The widespread deployment of high-speed networking and communications equipment has produced a large demand for various types of networking and communications components and subsystems. Included among these, are modules which are often referred to as optical transponders.
Optical transponders typically include components for both electrical signal processing, and components for transmission and reception of optical signals. Conventional optical transponders typically receive electrical signals in parallel, serialize the data represented by these signals, convert the serialized data into a light-based signal, and couple that signal to an outbound optical fiber. Similarly, conventional optical transponders, typically receive a serialized light-based data stream, convert that data stream to an electrical equivalent, de-serialize that data, and provide the de-serialized electrical data, i.e., data in a parallel format, to a plurality of output terminals. A common characteristic of optical transponders, and many other modern electronic circuits and systems, is that such equipment operates with signals having high frequencies, such as those in the GHz range and above.
Unfortunately, at very high frequencies, the performance, or operational characteristics, of electronic circuits and systems, including but not limited to products such as optical transponders, is limited by impedance mismatches that exist within those electronic circuits and systems. In some instances, impedance mismatches occur between conductive traces and various components which make electrical contact with those traces.
What is needed are methods and apparatus for constructing high frequency circuits with reduced impedance mismatches between components and the conductive traces to which those components are coupled.